On May 27, during the Science and Technology Activity Week in the Inner Mongolia Autonomous Region, Inner Mongolia Product Quality Inspection and Research Institute opened some laboratories to the public and demonstrated on-site how to test “acid” for yogurt.
On the testing instrument, the staff adds 20ml of freshly boiled and cooled distilled water to a 10g yogurt sample, and titrates with a 0.1mol/L sodium hydroxide standard solution. The pH value is set to 8.3 as the titration end point, and the volume of sodium hydroxide is consumed. , To calculate the acidity of the yogurt sample, the sample is qualified if the acidity is ≥70.
The staff also demonstrated two methods of machine titration and manual titration.
According to the staff, the acidity of yogurt is too high to cause the product to become rancid. The acidity is related to the taste, and has nothing to do with the quality.
Consumers should pay attention to the shelf life and added ingredients when choosing yogurt, such as lactic acid bacteria, fat, protein, and the number of added viable bacteria.
(Reporter Wu Yana produced Ma Zhiyuan)
Editor in charge: [Bian Liqun]